Reflection type optical filter with working wavelength of 121.6 nm

Abstract

The invention belongs to the technical field of optics, and particularly relates to a reflective optical filter with the working wavelength of 121.6 nm. The reflective optical filter is made of fused quartz glass, and the roughness of the surface, through which light passes, of the reflective optical filter is smaller than 1 nm. The 121.6 nm optical filter is prepared on the basis of the fused quartz glass, the problem of environmental adaptability of a traditional thin film optical filter is solved, and the 121.6 nm optical filter can be applied to extremely severe environments such as the sun close-range observation environment.

Description

Technical Field

[0001] The invention belongs to the field of optical technology, and in particular relates to a reflective filter with an operating wavelength of 121.6 nm. Background Art

[0002] Light emitted by a light source typically includes spectral lines in multiple wavelength bands. To obtain high-purity target spectral lines, filters are typically used in optical systems. Filters are generally classified by the direction of the light path: reflective and transmissive. Based on their filtering mechanism, filters are generally divided into thin-film interference filters and absorption filters. Thin-film interference filters utilize the interference principle of multilayer films to achieve light filtering and primarily include dielectric filters, FP filters, and metal-induced filters. Absorption filters utilize the absorption properties of thin films or colored glass to achieve light filtering.

[0003] When used in special scenarios such as space environments and laser systems, filters often need to possess excellent stability to withstand the effects of harsh environmental factors such as high-energy particle bombardment, ultraviolet radiation damage, and atomic oxygen corrosion. In scenarios involving close-range solar detection, filters also need to be resistant to high temperatures. Such applications typically utilize thin-film filters, requiring the use of stable materials and appropriate thin-film deposition methods. Post-processing processes such as annealing and laser irradiation are also required to enhance the film's density and improve its adaptability to extreme environments.

[0004] The 121.6nm Lyman-alpha line of hydrogen is a key detection target for space-based solar observations. For this spectral line, Al / MgF2 transmissive thin-film filters and LaF3 / MgF2 reflective thin-film filters are commonly used. However, traditional thin-film filters often suffer from performance degradation in harsh application scenarios. Summary of the Invention

[0005] In light of this, the present invention aims to provide a reflective filter operating at a wavelength of 121.6 nm to address the performance degradation often faced by traditional thin-film filters in harsh application scenarios. This 121.6 nm filter, fabricated from fused quartz glass, addresses the environmental adaptability issues of traditional thin-film filters and can be used in extremely harsh environments, such as close-up observation of the sun.

[0006] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0007] A reflective filter with an operating wavelength of 121.6 nm is made of fused quartz glass, and the roughness of the surface through which light passes in the reflective filter is less than 1 nm.

[0008] Furthermore, the surface of the reflective filter through which the light passes is polished so that the roughness of the surface of the reflective filter through which the light passes is less than 1 nm.

[0009] Furthermore, the polishing means used in the polishing process include mechanical polishing and / or chemical polishing.

[0010] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0011] The present invention creates a reflective filter with an operating wavelength of 121.6 nm, primarily to address the space environment adaptability issues faced by conventional 121.6 nm thin-film filters. This 121.6 nm filter, fabricated from fused quartz glass, boasts a reflectivity of 17.3% at 121.6 nm, a bandwidth of approximately 40 nm, and excellent environmental resistance, withstanding erosion by high-energy protons, electrons, and atomic oxygen, as well as damage from gamma rays and ultraviolet radiation. In extremely harsh application scenarios, such as close-range observation of the sun, it offers more stable performance than conventional thin-film filters. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0013] Figure 1 This is a schematic structural diagram of a reflective filter with an operating wavelength of 121.6 nm according to an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the reflectivity curve of the reflective filter described in an embodiment of the present invention in the far ultraviolet band.

[0015] Description of reference numerals:

[0016] 1. Reflective filter. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0022] The space solar observation environment is exposed to high-intensity vacuum ultraviolet (VUV), extreme ultraviolet (EUV), X-ray radiation, as well as high-energy charged particles (protons and electrons) and solar wind particles. These factors can directly damage the structure of thin film materials, leading to performance degradation through mechanisms such as high-energy radiation damage, thermal stress failure, vacuum environment degradation, and chemical instability. Fused silica glass, with its single, uniform covalent network structure, high-energy Si-O bonds, extremely low thermal expansion coefficient, high purity, and high mechanical strength, fundamentally avoids the inherent defects of multilayer films, such as multiphase interface fragility, material stability differences, and thermal stress mismatch. However, fused silica glass is primarily composed of silicon dioxide (SiO2), whose UV absorption edge is approximately 160nm. At 121.6 nm (the vacuum ultraviolet band), fused silica causes significant light loss due to intrinsic absorption. Furthermore, the refractive index of fused silica at 121.6 nm is approximately 1.46, and its surface single-shot reflectivity is only approximately 4%. Currently, there are no technological breakthroughs in using fused silica glass as an independent reflective element to form a reflective filter 1. The present invention polishes both surfaces of the fused silica glass (the surfaces through which light passes) to a surface roughness of less than 1 nm, thereby forming a reflective filter 1 operating at a wavelength of 121.6 nm.

[0023] like Figure 1 As shown, the present invention provides a reflective filter 1 with an operating wavelength of 121.6 nm. The material of the reflective filter 1 is fused quartz glass, and the roughness of the surface through which light passes in the reflective filter 1 is better than 1 nm.

[0024] In some embodiments, the surface of the reflective filter 1 through which the light passes is polished so that the roughness of the surface of the reflective filter 1 through which the light passes is less than 1 nm.

[0025] In some embodiments, the polishing process may include mechanical polishing and / or chemical polishing.

[0026] like Figure 2 As shown, the reflective filter 1 provided by the present invention has a reflectivity (represented by R) of 17.3% at 121.6 nm, a peak wavelength of 119.6 nm, a peak reflectivity of 19.1%, and a bandwidth of approximately 40 nm. It exhibits excellent resistance to high-energy protons, electrons, atomic oxygen, gamma rays, and ultraviolet radiation. After irradiation, the reflectivity remains unchanged, and the bandwidth remains unchanged, demonstrating the excellent performance of the reflective filter 1 provided by the present invention.

[0027] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0028] The above specific implementations do not limit the scope of protection of the present invention.

[0029] It should be understood by the technician that various modifications may be made depending on the design requirements and other factors.

[0030] Any modification, combination, sub-combination and substitution made within the spirit and principle of the present invention

[0031] Modifications, equivalent replacements and improvements should all be included in the protection scope of the present invention.

Claims

1. A reflective filter with an operating wavelength of 121.6 nm, characterized in that: The reflective filter is made of fused quartz glass, and the roughness of the surface of the reflective filter through which light passes is less than 1 nm.

2. The reflective filter with an operating wavelength of 121.6 nm according to claim 1, characterized in that: The surface of the reflective filter through which the light passes is polished so that the roughness of the surface of the reflective filter through which the light passes is less than 1 nm.

3. The reflective filter with an operating wavelength of 121.6 nm according to claim 2, characterized in that: The polishing methods used in the polishing process include mechanical polishing and / or chemical polishing.

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